TECTONIC EVOLUTION OF THE LHASA TERRANE, SOUTH TIBET SINCE MIDDLE TRIASSIC: TRANSITION FROM OCEAN-CONTINENT MULTIPLE SUBDUCTION TO CONTINENT-CONTINENT COLLISION

2017 ◽  
Author(s):  
Zhiqin Xu ◽  
◽  
Xuxuan Ma
Keyword(s):  
Tectonic Evolution ◽  
Middle Triassic ◽  
Lhasa Terrane ◽  
South Tibet

Late Cretaceous tectonothermal evolution of the southern Lhasa terrane, South Tibet: Consequence of a Mesozoic Andean-type orogeny

2018 ◽  
Vol 730 ◽  
pp. 100-113 ◽  
Author(s):  
Xin Dong ◽  
Ze-ming Zhang ◽  
Reiner Klemd ◽  
Zhen-yu He ◽  
Zuo-lin Tian
Keyword(s):  
Late Cretaceous ◽  
Lhasa Terrane ◽  
Andean Type ◽  
South Tibet

scholarly journals Overview of Cordilleran oceanic terranes and their significance for the tectonic evolution of the northern Cordillera

2021 ◽  
Author(s):  
A Zagorevski ◽  
C R van Staal ◽  
J H Bédard ◽  
A Bogatu ◽  
D Canil ◽  
...  
Keyword(s):  
Continental Margin ◽  
Tectonic Evolution ◽  
Middle Triassic ◽  
Passive Margin ◽  
Suprasubduction Zone ◽  
Ophiolitic Rocks ◽  
Juvenile Crust ◽  
Tectonic Framework ◽  
Tectonic Reconstructions ◽  
Stratigraphic Nomenclature

Ophiolite complexes are an important component of oceanic terranes in the northern Cordillera and constitute a significant amount of juvenile crust added to the Mesozoic Laurentian continental margin during Cordilleran orogenesis. Despite their tectonic importance, few systematic studies of these complexes have been conducted. Detailed studies of the pseudostratigraphy, age, geochemistry, and structural setting of ophiolitic rocks in the northern Cordillera indicate that ophiolites formed in Permian to Middle Triassic suprasubduction zone settings and were obducted onto passive margin sequences. Re-evaluation of ophiolite complexes highlights fundamental gaps in the understanding of the tectonic framework of the northern Cordillera. The previous inclusion of ophiolite complexes into generic 'oceanic' terranes resulted in significant challenges for stratigraphic nomenclature, led to incorrect terrane definitions, and resulted in flawed tectonic reconstructions.

Metamorphism and tectonic evolution of the Lhasa terrane, Central Tibet

2014 ◽  
Vol 25 (1) ◽  
pp. 170-189 ◽  
Author(s):  
Z.M. Zhang ◽  
X. Dong ◽  
M. Santosh ◽  
G.C. Zhao
Keyword(s):  
Tectonic Evolution ◽  
Lhasa Terrane ◽  
Central Tibet

Ordo-Silurian assemblage in the Indochina interior: Geochronological, elemental, and Sr-Nd-Pb-Hf-O isotopic constraints of early Paleozoic granitoids in South Laos

2020 ◽  
Vol 133 (1-2) ◽  
pp. 325-346 ◽  
Author(s):  
Yuejun Wang ◽  
Yuzhi Zhang ◽  
Xin Qian ◽  
Vongpaseuth Senebouttalath ◽  
Yang Wang ◽  
...  
Keyword(s):  
Tectonic Evolution ◽  
High Field ◽  
Igneous Rocks ◽  
Early Paleozoic ◽  
Isotopic Data ◽  
High Field Strength ◽  
Tectonic Zone ◽  
Type Granite ◽  
Juvenile Crust ◽  
South Tibet

Abstract In order to verify the early Paleozoic accretionary assemblage in the Indochina interior and constrain the Prototethyan tectonic evolution in Southeast Asia, this study presents a set of new U-Pb geochronological, elemental, and Sr-Nd-Pb-Hf-O isotopic data for the fifty-two representative granitoids in South Laos. The granitoids from the Kontum terrane, Tam Ky-Phuoc Son tectonic zone, and southern Truong Son igneous zone in South Laos yield the crystallization ages of 464–485 Ma, 455–471 Ma, and 427–446 Ma, respectively, with a northerly younging trend within the Indochina interior. They are mainly monzogranite with A/CNK = 0.96–1.99 and K2O > Na2O, which are marked by enrichment in large-ion lithophile elements and depletion in high field strength elements with remarkable Nb-Ta, Sr-P, and Ti negative anomalies. Their initial 87Sr/86Sr ratios range from 0.70510 to 0.71559, εNd(t) from −9.5 to −3.0, (206Pb/204Pb)i from 18.65 to 19.72, (207Pb/204Pb)i from 15.66 to 15.80, and (208Pb/ 204Pb)i from 38.84 to 39.79. The corresponding zircon ɛHf(t) and δ18O values are in the range of −10.6 to +1.0 and 6.88‰ to 8.94‰, respectively. In addition, their Sr-Nd-Pb and Hf-O isotopic compositions are generally similar with those of time-equivalent granitoids in South Tibet and SW Yunnan, China, and synchronous mafic-intermediate igneous rocks in South Laos, but distinctive from those of the supracrustal sedimentary-derived South China Paleozoic granite and Lincang-Sukhothai S-type granite. The early Paleozoic granitoids in South Laos might have originated from a mixed source of the wedge-derived juvenile crust coupled with supracrustal materials. All these data synthetically suggest the southward subduction of the Tam Ky-Phuoc Son Ocean and the northerly on-growing Ordo-Silurian accretionary orogenesis within the previously defined “single-ancient” Indochina block. The assemblage of the Indochina block might initiate at ca. 430 Ma in the Silurian and terminate in the Early-Middle Devonian.

Early Cretaceous bimodal volcanic rocks in the southern Lhasa terrane, south Tibet: Age, petrogenesis and tectonic implications

Lithos ◽  
2017 ◽  
Vol 268-271 ◽  
pp. 260-273 ◽  
Author(s):  
Chao Wang ◽  
Lin Ding ◽  
Zhi-Chao Liu ◽  
Li-Yun Zhang ◽  
Ya-Hui Yue
Keyword(s):  
Early Cretaceous ◽  
Volcanic Rocks ◽  
Lhasa Terrane ◽  
Tectonic Implications ◽  
South Tibet

Late Neoproterozoic thermal events in the northern Lhasa terrane, south Tibet: Zircon chronology and tectonic implications

2011 ◽  
Vol 52 (5) ◽  
pp. 389-405 ◽  
Author(s):  
Xin Dong ◽  
Zeming Zhang ◽  
M. Santosh ◽  
Wei Wang ◽  
Fei Yu ◽  
...  
Keyword(s):  
Lhasa Terrane ◽  
Tectonic Implications ◽  
Late Neoproterozoic ◽  
South Tibet

Superimposed deformation of the Solonker Belt and nearby regions in western Inner Mongolia, China

2018 ◽  
Vol 156 (5) ◽  
pp. 811-832 ◽  
Author(s):  
GUANZHONG SHI ◽  
CHAO LIANG ◽  
HUA WANG ◽  
CHUANYAN HUANG
Keyword(s):  
Structural Analysis ◽  
Tectonic Evolution ◽  
Inner Mongolia ◽  
Late Jurassic ◽  
Middle Triassic ◽  
Orogenic Belt ◽  
Far Field ◽  
Quartz Veins ◽  
Central Asian ◽  
Two Stages

AbstractThe deformation of the Solonker Belt and nearby regions is helpful for understanding the tectonic evolution of the Central Asian Orogenic Belt. This study carried out structural analysis in the Mandula and Ganqi areas of western Inner Mongolia, including the Solonker Belt, the Southern Orogenic Belt and the northern Yinshan Belt (Langshan range). Our results reveal that the Solonker Belt, the Southern Orogenic Belt and the northern Yinshan Belt underwent two stages (D1 and D2) of deformation during the Mesozoic period. The D1 stage produced the NNE-directed thrusts and asymmetric folds, indicating a NNE–SSW contraction. The northern Yinshan Belt, the Southern Orogenic Belt and the Solonker Belt formed as a series of NNE-verging tectonic nappes. The D2 stage developed the NE-trending folds and the SE- or NW-directed thrusts that cross-cut the D1 structures. The two events of nearly orthogonal or oblique shortening gave rise to the superimposed structures (e.g. fold interference patterns). The quartz veins that filled the fractures of the D1 deformation contain zircons of Middle Triassic U–Pb ages. The new dating data, along with the regional sedimentary hiatus, led us to infer that the D1 stage of deformation occurred in Middle Triassic time and the D2 stage occurred in Late Jurassic time. We consider that the D1 stage of deformation resulted from a convergent event, which might be related to the closure of the Palaeo-Asian Ocean or limited, narrow ocean basins; and the D2 stage of deformation was the far-field result of subduction of the Palaeo-Pacific Ocean and the closure of the Mongol-Okhotsk Ocean.

Geology of the Cadwallader Group and the Intermontane–Insular superterrane boundary, southwestern British Columbia

1987 ◽  
Vol 24 (11) ◽  
pp. 2279-2291 ◽  
Author(s):  
Margaret E. Rusmore
Keyword(s):  
British Columbia ◽  
Middle Jurassic ◽  
Tectonic Evolution ◽  
Middle Triassic ◽  
Upper Triassic ◽  
Tectonic Block ◽  
Volcanic Arc ◽  
Arc Volcanism ◽  
Clastic Rocks ◽  
Tectonic Settings

Several lower Mesozoic, fault-bounded units separate the Intermontane and Insular superterranes in southwestern British Columbia. Detailed study of one of these Mesozoic units, the Cadwallader Group, helps clarify the boundary between the superterranes and establish the tectonic evolution of southwestern British Columbia. The Cadwallader Group is the oldest unit in an Upper Triassic through Middle Jurassic volcanic and sedimentary tectono-stratigraphic terrane. Two formations, the Pioneer and the Hurley, compose the Cadwallader Group; the previously recognized Noel Formation is no longer considered valid. The Pioneer Formation contains pillow basalt, flows, and basalt breccia. Siltstone, sandstone, conglomerate, and minor amounts of limestone megabreccia and basalt belonging to the Hurley Formation conformably overlie the Pioneer. The Hurley spans latest Carnian or earliest Norian to middle Norian time. Two episodes of deformation affected the Cadwallader, and a thrust fault separates the group from slightly younger clastic rocks of the Tyaughton Group. Similarities in clastic rocks indicate the Tyaughton was deposited on the Cadwallader; together the units form the Cadwallader terrane. Basalts and clastic rocks in the terrane record deposition in or near a Carnian to earliest Norian volcanic arc. Volcanism waned later in the Norian, but presence of the arc is preserved in the clastic rocks.Oceanic rocks of the Middle Triassic to Middle Jurassic Bridge River terrane became juxtaposed with the Cadwallader terrane in Middle Jurassic time, after which the terranes functioned as a single tectonic block. Contrasting volcanic histories suggest that the Cadwallader terrane was not accreted to the Intermontane superterrane until Middle Jurassic or Early Cretaceous time, although the similar tectonic settings of Stikinia and the Cadwallader terrane allow a common earlier history. The Cadwallader terrane is not part of either the Alexander terrane or Wrangellia, and so the inboard margin of the Insular superterrane must lie west of the Cadwallader terrane.

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